Arsenal have shown sporadic signs of improvement this season, but in order to stay competitive alongside their fellow European giants, this summer transfer window must be an efficient one.

The Gunners' squad doesn't have much by way of gaping holes in it, but it's crucial that what deficiencies there are get replaced with quality signings.

As ever, the club have been linked with some of the biggest players in Europe, and even this far in advance, transfers can begin to take shape as clubs look to tie up deals before the World Cup.

This week, the biggest stories linked with ArseneWenger's side come from the Bundesliga, with both Borussia Dortmund and Bayern Munich stars in the discussion.

IlkayGundogan, Borussia Dortmund

Alex Grimm/Getty Images

With Robert Lewandowski heading to Bayern Munich on a free transfer this summer, Borussia Dortmund will be eager to ensure that another one of their stars, IlkayGundogan, isn't allowed to leave on identical terms when his contract expires next summer.

Is Gundogan worth the risk after missing the 2013-14 campaign?

Yes, he can recover to be better than ever.No, it's best to invest in a fitter asset.Submit Votevote to see results

Is Gundogan worth the risk after missing the 2013-14 campaign?

Yes, he can recover to be better than ever.

75.8%

No, it's best to invest in a fitter asset.

24.2%

Total votes: 1,030

Club CEO AkiWatzke shed some new light on the player's ongoing negotiations when speaking with German newspaper Sport Bild (h/t ESPN FC's Stephan Uersfeld) this week:

“We would like to prolong with Ilkay. He has an offer on the table. The decision will certainly not wait until the summer.”

Gundogan has played just 56 minutes of league football this season, which has affected discussions between him and the club, but Watzke's comments would appear to suggest that unless an extension can be agreed upon, there's a chance he could be sold this summer.

Should Wenger feel safe in risking a move for the central midfield star, suffering with a recurring spinal injury this term, a cut-price deal could beckon in the months to come.

Antoine Griezmann has handed Arsenal a recruitment boost after the Real Sociedad winger took to his personal Twitter account to deny rumours he has already agreed to a move to Paris Saint-Germain this summer.

The Parisian outfit have made a habit of luring the best talents that France and Ligue 1 have to offer, but it appears Griezmann won't be drawn on such speculation:

After having seen the news about my possible agreement with PSG, I want to deny any type of agreement or conversations with this club. The rumours of a possible signing with PSG are not correct, there has been no contact or decision to leave.

While Griezmann's commitment to La Real is admirable, the Gunners, whom Corrigan mentions as one of the Frenchman's suitors, will take comfort in knowing his services may still be up for grabs this summer.

The French ranks under Wenger's command are already strong—with Olivier Giroud, Mathieu Flamini, BacarySagna and YayaSanogo in the squad—but Arsenal may find it difficult to compete with the salary offers that Qatari-owned PSG will be able to make.

Mario Mandzukic, Bayern Munich

Arsenal were thought to have stolen a march on Mario Mandzukic's signature last week when it was reported by Metro that the striker's agent was in London for talks with the North London club.

However, it's emerged this week that Bayern Munich want to hang onto their goalscorer, with chairman Karl-Heinz Rummenigge stating that the player has loyalties to fulfill, per Colin Harvey of the Daily Star:

"Mario Mandzukic is under contract with our club. I am definitely aware that many clubs have started to show an interest in Mario's services, but I believe he will be with our club way beyond the end of this season."

There was the notion that Lewandowski's impending arrival at the Allianz Arena would immediately dislodge Mandzukic's position, and OptaFranz shows just how thriving the Bayern attack will be with both players comprising:

18 - The only Bundesliga players to score 18 goals in competitive matches in 2013/14 are Mario Mandzukic and Robert Lewandowski. Rivals.

Mandzukic, as can be seen above, was involved in a training incident with Bastian Schweinsteiger earlier this year that may have damaged his position in the squad, but it seems the newly crowned Bundesliga champions may find room in their plans for the Croatian yet.